"In a complex global environment, RPA [remotely piloted aircraft] pilots will always be in demand," Air Force Secretary Deborah Lee James said in a release Wednesday. "Remarkable airmen have ensured the success of the MQ-1/9 programs. We now face a situation where if we don't direct additional resources appropriately, it creates unacceptable risk."

Air Force spokesman Lt. Col. Chris Karns said that the critical skills retention bonus will only be offered to pilots in the 18X Air Force specialty code.

18X pilots who are reaching the end of their initial six-year commitment can get the bonuses by agreeing to serve another five or nine years. They will get $15,000 a year, meaning they will get either $75,000 or $135,000, depending on how long they agree to stay. They can also choose to get 50 percent of their bonus as an upfront lump-sum payment.

The 80 undergraduate pilot training graduates directed into drone squadrons will serve one assignment tour — typically lasting three years — before being offered the opportunity to move to a manned aircraft.

The last time the Air Force did this was between 2009 and 2011. About 30 percent of the 248 pilots who were given the opportunity to fly manned aircraft at the end of their tours decided to remain drone pilots, Karns said.

The Air Force hopes these moves will lessen the strain on overworked drone squadrons. Fighter pilots fly an average of 250 hours per year, Karns said. But drone pilots fly about 900 hours per year, and are taxed by combatant commanders' ever-growing need for more intelligence, surveillance and reconnaissance capabilities.

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"The RPA community has been operating at surge capacity for eight years," Karns said.

And the Air Force isn't producing enough drone pilots to fill those needs. In an email, Karns said the Air Force's current operations tempo requires it to produce about 300 active-duty pilots per year, but it is only turning out 190 each year.

RPA pilots got some relief in April, when Defense Secretary Ash Carter approved a reduction of combat air patrols, Karns said. At that point, drone pilots flew 65 CAP missions per day, but they're now down to 61 per day, and are expected to hit 60 in October.

"It's one of those situations where this decision needed to be made to ensure the long-term viability of the RPA enterprise, and to be be able to meet current and long-term combatant commander needs," Karns said. "This will put us in a position to get healthy and be able to provide enhanced support going into the future."

Undergraduate pilot training graduates will be chosen for drone duty based on their performance, their preference and the needs of the Air Force, Karns said. The highest-performing pilots will have the best shot of getting their pick of platforms, he said. But the Air Force will assign some pilots to drone duty to fill those slots.

The Air Force now plans to only steer pilot graduates to drone duty for one year.

Pilots who accept the bonus will no longer be eligible for the expanded monthly flight pay James approved in January, Karns said. That change increased the maximum amount 18X drone pilots can get from $650 per month to $1,500, if they keep flying unmanned aircraft beyond their six-year commitments. But pilots getting the bonus will still get the standard $650 monthly flight pay.

The extra monthly flight pay adds up to $10,200 per year, meaning that by accepting the new $15,000 annual bonus, these pilots would get an extra $4,800 per year.

The bonuses are similar to, but different from the up to $225,000 Aviator Retention Pay bonus that this year became available to some 11U RPA pilots.